Using nuclear energy to produce hydrogen, desalinate seawater and heat buildings can further enhance nuclear power’s contribution to climate action while also boosting its economic viability, speakers at a recent IAEA webinar said.
Nuclear power accounts for around one-third of global low carbon electricity production. But in addition to powering millions of homes and businesses, nuclear power plants (NPPs) produce heat that can also be directly used for a wide range of industrial applications as well as the production of chemicals, processes which have historically been powered by fossil fuels.
“Mitigating climate change requires a comprehensive approach to decarbonization beyond just implementing low carbon electricity systems,” said Ibrahim Khamis, a senior nuclear engineer at the IAEA. “Part of the heat produced at nuclear power plants can be redirected from electricity production to provide heat for buildings, drive industrial production, and more.”
Nuclear energy cogeneration involves using part of the heat from an NPP for non-electric applications by coupling the plant with other systems, such as for desalination. This enhances the NPP’s overall efficiency as more of its energy is utilized, while reducing carbon emissions in sectors which typically rely on fossil fuels.
As countries plan their low carbon energy strategies for the future, cogeneration is emerging as an attractive option for decarbonizing while enhancing both the efficiency and profitability of flexible energy systems involving a combination of nuclear and renewables. Utilizing the heat produced in NPPs for applications such as district heating and hydrogen production not only reduces carbon emissions, but it also provides another source of revenue for NPP operators, enhancing their bottom line and contributing to the sustainability of nuclear power.
During the webinar on 22 July, attended by more than 250 participants from 55 countries, speakers from Canada and Japan discussed what their research organizations are doing to assess the feasibility of cogeneration and push innovation in non-electric applications of nuclear power forward.
Gina Strati, Director of the Energy Program at Canadian Nuclear Laboratories (CNL), talked about how CNL is analysing how hybrid systems incorporating cogeneration can help Canada meet its energy needs, including in remote communities and at mines. CNL’s Hybrid Energy System Optimization (HESO) model, developed as part of a project launched in 2018, is designed to assess different energy mix scenarios with the aim of minimizing carbon emissions and cost. The model considers demand for both electricity and thermal energy as well as hydrogen production and various storage options.
Hydrogen is used for a variety of applications, including the production of synthetic fuels, the manufacture of semiconductors, and to power fuel cell vehicles. Fuel cell vehicles, unlike their fossil-fuel driven counterparts, only emit water and heat during operation.
“The HESO model has been used to analyse scenarios which include increased penetration of wind energy in Canada, the electrification of hot water heaters in Ontario province, electrification and district heating in remote communities and low carbon steel production,” said Strati. “Hydrogen production in particular can play an important role in maximizing resources, including by producing hydrogen when there is less demand for electricity.” CNL is also conducting research on hydrogen, including its production, storage, safety and utilization, she added.
CNL’s Clean Energy Development Innovation & Research (CEDIR) park, expected to be operational by the middle of this decade, will serve as a cogeneration demonstration site to test the viability of low carbon hybrid energy systems with small modular reactors (SMRs) and their capability to help meet a range of energy needs across Canada.
Xing Yan, Deputy Director of the Reactor Systems Design Department at the Japan Atomic Energy Agency (JAEA), discussed Japan’s work in developing advanced reactors, including the High Temperature Gas Cooled Reactor (HTGR) and the High Temperature Engineering Test Reactor (HTTR), to help expand applications of nuclear power and decrease carbon emissions. Advanced reactors capable of operating at very high temperatures may be ideal for not only power generation but also non-electric applications as the high temperature heat they produce can bolster the efficiency of processes such as hydrogen production, allowing for greater production in a shorter period of time.
“Industrial processes make up a significant share of overall carbon emissions, and there is great potential to abate these missions with nuclear power. In Japan, steelmaking alone accounts for around 12% of Japan’s total greenhouse gas emissions,” said Yan. “Only about 1% of nuclear energy worldwide is currently used for non-electric applications, and we hope to increase this share significantly with deployment of our advanced high temperature reactors.”
JAEA has carried out thermochemical hydrogen production with a high temperature heat source, producing 20 liters of hydrogen per hour over a 31-hour period in the first trial in 2016. With ongoing improvements in the technology, a 100 liter per hour test is planned for 2020. The thermochemical method uses high temperature heat to induce chemical reactions that produce hydrogen. This process is highly efficient and may be ideal for large scale, sustainable hydrogen production.
The pre-licensing basic design of a hydrogen cogeneration facility to connect to the HTTR was completed in 2017, and there are plans to license a nuclear cogeneration system once a demonstration of performance and cost has been completed. This system, known as the GTHTR300, is being designed for multiple cogeneration purposes, including heat applications such as desalination as well as hydrogen production.
The webinar was the third entry in a series on nuclear technology breakthroughs for the 21st century. Recordings of the first webinar, on prospects and issues in nuclear-renewable integrated energy systems, as well as the second on small modular reactors in integrated energy systems, are available here and here.